Flooring Calculator

How the flooring calculator works

The first step for any floor covering is the floor area:

Area (m²) = length (m) × width (m)

Once you have the area, add a waste allowance and divide by the coverage of one pack to find how many packs to buy.

Worked example: laminate for a 5.2 m × 4.1 m living room

1. Area: 5.2 × 4.1 = 21.32 m²
2. Waste for a straight lay: 7%, giving 21.32 × 1.07 = 22.81 m²
3. Pack coverage (from the box): 2.13 m²
4. 22.81 ÷ 2.13 = 10.7, so buy 11 packs

Waste allowance by product and layout

Installation points that affect quantity

• Expansion gap: floating floors need a gap at walls (often about 10 mm), hidden by skirting or scotia.
• Direction: planks usually run toward the main light source or along the longest wall. Choosing lengths that suit the room reduces offcuts.
• Underlay: buy for the full area, plus overlaps at the joins.
• Acclimatisation: leave timber and laminate in the room for the time the manufacturer specifies before laying.

Irregular rooms

Split the room into rectangles, work out each area, and add them up. Include wardrobes and pantry floors if the flooring runs through them.

Common mistakes

• Buying exactly the floor area, then running short on the last row.
• Forgetting stairs, which need special nosings and are usually priced per step.
• Mixing batches. Buy all packs at once so the colour matches.

How much extra flooring should I buy?

Allow 5–10% for straight lays and 15–20% for herringbone or diagonal patterns.

How do I calculate flooring for an L-shaped room?

Split it into two rectangles, calculate each area, and add them together before adding waste.

Should I keep leftover flooring?

Yes. Keep at least one pack for repairs, because matching the exact batch later is often impossible.

Written by Sam Alex, civil engineer. About the author